1. Field of the Invention
The present invention relates to an electrical connector, and more particularly, but not by way of limitation, to a glow plug connector for operably connecting a power source to a model engine glow plug.
2. Description of the Prior Art
For many years, hobbiests have been utilizing a small internal combustion engine for driving model airplanes, cars and the like. The ignition system for these small engines consists of a glow plug which is threadedly mounted through the head of the engine into open communication with the engine cylinder. The plug comprises a metallic threaded body member and a center pole probe which is mounted through the center of the plug body and insulated therefrom. The inside end of the center pole is connected to the plug body by means of a filament wire which is used as a heating coil. In order to cause initial combustion within the engine cylinder, normally one pole of a 1.5 volt battery is connected to the center pole of the glow plug and the other pole of the battery is connected to the plug body or to the engine head for completing an electrical circuit through the filament wire of the glow plug. When the filament wire becomes sufficiently hot to cause ignition of the gases within the chamber the engine may be started. After sufficient engine heat is developed within the cylinder to keep the filament wire hot, the battery or power source may be disconnected from the glow plug, the engine heat being sufficient to sustain its own firing.
There are many ways to connect the battery leads to the glow plug arrangement but the most common is the use of lead wires having alligator type clips associated therewith. One alligator clip is connected to the center pole of the glow plug and the other to some metallic portion of the engine head. This method, while workable is undesirable and can even be dangerous. Unless great care is taken, the alligator clips may both come into contact with the cylinder head, thereby causing an electrical short. Further, usually associated with an engine of this sort is a fast turning propeller which may cause damage upon coming into contact with the electrical leads. Further, it is desirable for the leads to be disconnectable or with one hand since the other hand is needed to hold the model in place after the engine is started.
Other attempts have been made to develop a single unit connector which connects one lead of the battery through the center pole of the glow plug and the other lead to somewhere on the engine body to complete the circuit. However, most of these units have been unsuccessful in withstanding the vibration normally associated with starting of a model airplane type engine.